fix(tests): reduce React warnings and report replay output

Configure React act support in the webapp test setup and avoid
duplicating successful-test console output when merging CI reports.
Failed-test diagnostics and report results remain visible.

Mono-RevId: e49c5f83c379abe5b5618d1aceeb519dfdad5359

Author: carderne

.github/workflows/unit-tests-webapp.yml

@@ -191,4 +191,4 @@ jobs:
           merge-multiple: true
 
       - name: Merge reports
-        run: pnpm dlx vitest@"$(jq -r .devDependencies.vitest "$GITHUB_WORKSPACE/package.json")" run --merge-reports --pass-with-no-tests
+        run: pnpm dlx vitest@"$(jq -r .devDependencies.vitest "$GITHUB_WORKSPACE/package.json")" run --merge-reports --reporter=default --silent=passed-only --pass-with-no-tests

apps/webapp/test/setup.ts

@@ -2,6 +2,8 @@ import { vi } from "vitest";
 import type * as IORedisModule from "ioredis";
 import type * as TaskMetadataCacheModule from "~/services/taskMetadataCache.server";
 
+(globalThis as { IS_REACT_ACT_ENVIRONMENT?: boolean }).IS_REACT_ACT_ENVIRONMENT = true;
+
 // CI has no .env and no REDIS_HOST/REDIS_PORT, so import-time guards like
 // autoIncrementCounter.server.ts throw and their suites fail to collect. Default
 // the pair — the ioredis mock below forces lazyConnect, so nothing ever dials.